Transformable structure for producing a multi thread single line stitch and method and machine for its realization

ABSTRACT

A multi-thread single-line chain stitch line, consisting of at least three threads. This method provides for the formation of variable structures of stitches, based on varying sequences for the conjoining of several top threads, loaded to their individual needles, with several bottom threads, loaded to their individual loopers. The method suggests intertwining top threads between each other. The proposed stitch structure provides homogeneity of mechanical stresses in the stitch line, resulting in higher strength and durability. The machine to provide such stitch line comprises a revolver, bringing required needles to the operation point and intertwining threads during formation of the stitch line, and likewise comprising a revolver for bringing required loopers to the operation point. In one of the embodiments of the present invention, only three top threads are used, with the looper having no bottom thread loaded in it.

CROSS-REFERENCES TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

1. Field of the Invention

The present invention relates to the manufacture of equipment for sewingtechnologies and methods for the sewing industry, the embroidered goodsindustry, the knitted goods industry, the leather industry and the shoeindustry. The present invention comprises a technology for obtaining amulti-thread single-line chain stitch line.

2. Description of Prior Art and Existing Problems

Existing at present, chain stitch lines (presented in U.S. Pat. Nos.3,301,206; 3,753,410) have a limited number of threads (two threadsonly) being used in the line, and are limited in the variability of thestructure of the stitch, which in turn limits the possibilities foradjusting the stitch line structure to the operational requirements.Likewise, the existing machines, manufacturing two-thread single-linechain stitch lines, have limited functional possibilities (as presentedin U.S. Pat. Nos. 3,301,206; 3,753,410; 6,095,069).

The limited number of threads being used in the prior art stronglyhinders the potential for changes in the parameters of the stitch, whichare limited to changing the step of the stitch and the thread tension.

The contemporary chain stitch line used in sewing knitted goods is notvery reliable, and tends to deform the seam, causing corrugation, whichcreates the appearance of a defect in the finished product.

Another problem in sewing technology is the optimization of stitch lineproperties along its length. The loads to which the stitch is exposedare different in different areas of a sewn article. In addition, theconditions of the stitch line operation are different, whereas thestitch line remains uniform along its length under the existingtechnology. For example, an article, such as a sleeve, is subject tovarious deformations in different areas—stretching at the elbow andcorrugation at the bend. Also, the uniform stitch line often joinsseveral layers of material, while the materials can be of different type(woven fabric, knitted fabric, leather, etc.). Thus, although theaverage properties of the uniform stitch line are intended to covervariable requirements, such factors ultimately limit the technologicalpossibilities for creating new goods without the existing difficulties.

Further, the existing chain stitch structure results in unevendeformation under stretching, where alternating stretched and squeezedareas are created (stretched areas occur around the perforation in thematerial, i.e. in the point of conjunction of the top and bottomthreads, while the squeezed areas occur in the interval between twoperforations). Such uneven deformation of the seam causes corrugation.

Known stitch lines provide stretch ability due to the stretch ability ofthe threads used in the line and deformation of the sewn material.

Thus, the main drawbacks of the contemporary single-line chain stitchline, which limit its application and degrade its operational propertiesand appearance of the finished product, are as follows:

-   -   1. Poor functional properties, which cannot be optimized along        the stitch line length, especially under conditions of        complicated design and variable operating conditions;    -   2. Seam corrugation in the operation process;    -   3. Low ability to stretch; and    -   4. Limitations in controlling the stitch line/seam properties.

The aim of the present invention is a further improvement in the classof the chain stitch, due to the elimination of the drawbacks describedabove, by using the following principles:

-   -   1. The elimination of corrugations due to mutual compensation of        stretch and compression zones, based on the structure of the        stitch;    -   2. Increased stretch ability of the stitch line by replacing a        rigid bond in the interval between perforations with a flexible        one;    -   3. The introduction of duplicating bonds, thereby increasing the        reliability of the stitch line;    -   4. Variability of the stitch structure, by varying the sequence        in the conjunction of the top and bottom threads, which allows a        change in the structure of the stitch along the length of the        stitch line for the optimization of the operational properties        of the seam in its different areas; and    -   5. Improved reliability of the stitch line due to intertwined        top threads and/or intertwined bottom threads.

These and other objects and advantages of this invention are describedin detail in the description of the invention contained herein.

BRIEF SUMMARY OF THE INVENTION

The present invention comprises variations in the manufacturing of chainstitch lines, with at least three threads involved, according to twomain versions: one version consisting of top and bottom threads, whichthreads are conjoined at the material perforation points; and anotherversion consists of top threads only.

In the first version, the top threads are joined with the bottom ones ina pre-determinable sequence, variable along the stitch line. This effectis obtained through the following:

-   -   1. By utilizing a pre-determinable sequencing program for        conjoining the top and the bottom threads. The program is        determined by the desired structure of the stitch line.    -   2. By the fact that each top thread is loaded into its own        needle and each bottom thread into its own looper.    -   3. By a means for sequentially engaging a required needle and of        another means for sequentially engaging a required looper        simultaneously, providing for conjunction of one of the top        threads with one of the bottom threads. A revolver can be used        for such means in both cases. Such revolver has needle bars        located along its periphery and oriented along its rotation        axis, and the other revolver has loopers located along its        periphery. Both revolvers are equipped with devices, providing        for enabling the desired needle-looper couple, which will        hereafter be called a “current couple.”    -   4. By a means for intertwining the top threads between each        other and a means for intertwining the bottom threads between        each other (as referenced below).

The considered stitch line structure consists of a system of several topand several bottom threads joined through the perforations in thematerial. Such structure provides for a mutual compensation of stretchedand squeezed areas of the material and eliminates corrugation of theseam. Another benefit is the potential for changing or transforming thestructure along the length of the stitch line in the process ofproducing the stitch line. It permits the optimization of the propertiesof the seam in terms of its appearance, stretch ability, wearresistance, etc.

The sequence of interaction of the top and the bottom threads isdetermined by the required structure of the stitches. The sequence ofinteraction can be controlled mechanically or digitally. These methodsof control and programming are well known and widely used—e.g., inknitwear fabrics manufacturing (U.S. Pat. Nos. 4,467,737 and 4,359,953).

The loading of every top thread into its needle and of every bottomthread into its looper can be provided by various methods used inconventional multi-thread sewing machines (U.S. Pat. Nos. 3,433,191 and4,993,335).

A means for sequentially engaging a required needle and a means forsequentially engaging a required looper simultaneously, providing forthe conjunction of one of the top threads with one of the bottomthreads, is not known from the prior art. Such means could be providedin various ways. One of the ways is taught in the present invention. Itcomprises a needle unit (mechanism) and a looper unit (mechanism).

The needle unit comprises a revolver (needle revolver) with needle barslocated along its periphery and oriented along its rotation axis. Thelooper unit also comprises a revolver (looper revolver), where theloopers are similarly located along its periphery. Both revolvers areequipped with a device which provides for enabling the current couple.Both revolvers are also provided with a means for turning and fixation.A Geneva wheel can be used for such purpose. (A Geneva wheel is awell-known mechanism in sewing machines; see, e.g., U.S. Pat. No.4,702,183).

The utilization of both revolvers, due to the rotation of the needlesand the loopers around the rotation axes of the respective revolvers,can provide for the respective intertwining of the top threads betweeneach other and of the bottom threads between each other.

The second basic version of the present invention implies a multi-threadsingle-line chain stitch line, consisting of at least three top threads,each top thread forming a loop at the material perforation point in apredetermined sequence, such loop being conjoined with the consequentloop at the consequent perforation point by means of a looper, with nothread being loaded in the looper.

DETAILED DESCRIPTION OF THE INVENTION AND DESCRIPTION OF THE DRAWINGS

The present invention can be easily understood from the detaileddescription of the preferred embodiment by reference to the attacheddrawings.

FIG. 1: This represents a general view of the structure of amulti-thread single-line chain stitch line (one of the possibleembodiments) in the formation process. The structure is obtained due tothe alternating connection of each top thread with the bottom threadthrough perforations (2) in the material (1) with intertwining (7) ofthe top threads (3 a, 3 b). Top threads (3 a, 3 b) are loaded intocorresponding needles (5 a, 5 b), and the bottom thread (4 a) is loadedin the looper (6 a). Loops of the top threads (3 a, 3 b) engage with thebottom thread (4 a). With the rotation of the needles (5 a, 5 b) at theangular speed of revolver rotation (ω) the intertwining of the threads(7) is obtained.

FIG. 2: Structure of a four-thread chain stitch line comprised of twotop threads (3 a, 3 b) and two bottom threads (4 a, 4 b).

FIG. 3: For better understanding the main steps in the formation of amulti-thread single-line chain stitch line, both top threads (3 a, 3 b)and the bottom thread (4 a) are drawn at different levels for easieridentification.

After bringing a current couple into the operating position:

A—passing of top thread (3 a) through material (1) by a needle (5 a);passing the loop of the bottom thread (4 a) by the looper (6 a) throughthe loop of the top thread (3 a);

B—extracting needle (5 a) out of material (1) engaging top thread (3 a)loop by looper (6 a);

C—shifting material (1) to extend the bottom thread loop (4 a) to thenext sequential perforation point;

D—passing of top thread (3 b) through material (1) by a needle (5 b),further passing the needle (5 b) together with the top thread (3 b)through the bottom thread (4 a) loop;

E—passing of bottom thread (4 a) by looper (6 a) through the top thread(3 b) loop and extracting needle (5 b) out of material (1).

FIG. 4: For better understanding the main steps in the formation of amulti-thread single-line chain stitch line, the two top threads (3 a, 3b) and the two bottom threads (4 a, 4 b) are drawn at different levelsfor easier identification.

After bringing a current couple into the operating position:

A—Passing of top thread (3 a) through material (1) at perforation (p#1),by required needle (5 a); engaging top thread (3 a) by required looper(6 a) with passing bottom thread (4 a) into the top thread (3 a) loop;thus forming the bottom thread (4 a) loop inside of the top thread (3 a)loop;

B—Extracting required needle (5 a) out of material (1) at (p#1) andshifting material (1) to stretch the top thread (3 a) loop by means oflooper (6 a); with this, the next current couple—needle (5 b) and looper(6 b)—provides interaction of top thread (3 b) and bottom thread (4 b);for which needle (5 b) brings top thread (3 b) through material (1) at(p #2), and looper (6 b) brings thread (4 b) through thread (3 b) loop.

C—Shifting material (1) again; bringing needle (5 a), which is anotherrequired needle, with the top thread (3 a), which is another requiredthread, into the operating position for said cycle, forming anothercurrent couple with the looper (6 a); with this, looper (6 a) stretchesthread (3 a) loop to the area of the next perforation (p#3); needle (5a) brings thread (3 a) through perforation (p#3) and providesinteraction of thread (3 a) loop by means of looper (6 a) with threads(3 a) and (4 a); with this looper (6 b) stretches thread (3 b) loop.

D—Thread (3 a) loop stretches thread (4 a) forming an element of thestitch.

E—Looper (6 a) brings thread (4 a) through thread (3 a) loop; with this,the next current couple (5 b) and (6 b) is being prepared.

F—Material (1) is shifted; with this, thread (3 b) loop is stretched bylooper (6 b) to the area of perforation (p#4); whereas needle (5 b) isbringing thread (3 b) through perforation (p#4), providing interactionof thread (3 b) loop with thread (4 b).

G—Thread (3 b) stretches thread (4 b) loop to the area of perforation(p#2) forming another element of the stitch.

H—Looper (6 b) brings thread (4 b) through thread (3 b) loop; with this,the next current couple (5 a) and (6 a) is formed.

I—Material (1) is shifted; looper (6 a) stretches thread (3 a) loop tothe area of perforation (p#5), looper (6 b) stretches thread (3 b) loopas well; needle (5 a) brings thread (3 a) through perforation (p#5) andthread (4 a) loop.

J—Looper (6 a) throws off thread (4 a) loop on needle (5 a) and thread(3 a).

K—Looper (6 a) brings thread (4 a) through thread (3 a) loop; with this,the next current couple (5 b) and (6 b) is being formed, and thematerial (1) is prepared to be shifted with further repetition of thecycle described in A-G.

(Note: If intertwining is required, after each extraction of the needlethe needle revolver rotates the required number of revolutions toprovide intertwining).

FIG. 7: Sewing machine—front view.

FIG. 8: Sewing machine—axonometric view.

FIG. 9: Needle revolver.

FIG. 10: Needle revolver consisting of two needle modules (16 a, 16 b)and module mounting device (modular needle revolver) (22).

FIG. 11: Needle module.

FIGS. 1-11 disclose: 1—sewn material; 2—perforation; (p#1, p#2, p#3,p#4, p#5—numbers of perforations); 3 a—first top thread; 3 b—second topthread; 3 c—third top thread; 4 a—first bottom thread; 4 b—second bottomthread; 5 a—first top thread needle; 5 b—second top thread needle; 5c—third top thread needle; 6 a—first bottom thread looper; 6 b—secondbottom thread looper; 7—thread intertwining; 8—needle unit (needlerevolver); 9—looper unit (looper revolver); 10—mechanism for discreterotation of the needle revolver (e.g. Geneva wheel); 11—mechanism fordiscrete rotation of the looper revolver (e.g. Geneva wheel); 12—needlebar (12 a—first needle bar; 12 b—second needle bar); 13—needle barengaging mechanism; 14—needle bar catching device; 15—needle barshoulder (15 a—first needle bar shoulder; 15 b—second needle barshoulder); 16 a—module of needle and thread feeder mechanism of thefirst needle; 16 b—module of needle and thread feeder mechanism of thesecond needle; 17—bobbin holder with bobbin; 18—thread tensionregulator; 19—thread take-up; 20—thread take-up eye; 21—thread take-updrive; 22—module mounting device; 23—shaft; 24—drum; 25—module housing;26—needle unit housing; ω—angular speed of revolver rotation.

The process of forming stitch lines according to the present inventioncan be performed by the following mechanisms and devices. The mechanismof discrete rotation of the needle revolver (10) turns needle unit(needle revolver) (8), bringing desired needle (e.g., 5 a) intooperating position; simultaneously, the mechanism of looper revolverdiscrete rotation (11) brings the desired looper (e.g., 6 a) intooperating position; thus, the current couple of needle (5 a) and looper(6 a) is enabled. With this, catching device (14) of mechanism (13)catches shoulder (15 a), thus enabling needle bar (12 a).

The sewing machine can be designed with:

-   -   solid needle revolvers (FIG. 9);    -   interchangeable revolvers having different numbers of needles        and loopers; and with    -   needle revolvers (modular needle revolvers) consisting of a        module-mounting device (22) and the desired number of needle        modules (16) (see FIG. 10 and FIG. 11).

The solid needle revolver (FIG. 9) is comprised of a cylindrical drum(24), which is driven by a rotation mechanism to make discrete rotations(10) via a shaft (23). Each needle (5) is supplied with individualneedle bars (12), bobbin holders (17), thread tension regulators (18),and thread take-ups (19). The motion of the thread take-up eye (20) issynchronized with the needle bar (12) via the thread take-up drive (21).

The modular needle revolver (FIG. 10 and FIG. 11) can be designed forvarious module-mounting device capacities. Modules (16) are mounted on amodule-mounting device (22), which is connected to the mechanism whichprovides for discrete rotation of the needle revolver (10). Alloperations are similar to the ones of the above-described solid needlerevolver (FIG. 6).

The module (FIG. 11) is comprised of the casing (25) enclosing theneedle bar (12) connected via the thread take-up drive (21) with thethread take-up (19). The casing (25) has a bobbin holder with bobbin(17) and thread tension regulator (18). The thread take-up drive (21)may be designed, for example, as a gear kit, transforming the motion ofcogs on the needle bar (12) and the thread take-up (19).

The novelty of the present invention is in obtaining various andvariable structures of chain stitch lines due to a pre-determinableconjunction of several top and several bottom threads. In theconventional chain stitch sewing machines, many methods are known formanufacturing conventional chain stitch lines. All of them areapplicable to this invention with modification, providing for theindividual interaction of needles and loopers, forming current couples.

While this invention has been described in terms of a specificembodiment thereof, it is to be understood that it is not limitedthereto, but rather only to the extent set forth hereafter in theclaims, which follow.

1. Manufacturing of a multi-thread single-line chain stitch line,consisting of at least three threads, which threads are conjoined at thematerial perforation points in a pre-determinable sequence, whichsequence is variable along the stitch line, which effect is obtained byutilizing a pre-determinable sequencing program for conjoining thethreads, and which program is determined by the desired structure of thestitch line.
 2. Manufacturing of a multi-thread single-line chain stitchline, as claimed in claim 1, consisting of at least two top threads andat least one bottom thread, where said top threads on the top side ofthe material are independent of each other and/or intertwined betweeneach other (as shown in FIG. 1).
 3. Manufacturing of a multi-threadsingle-line chain stitch line, as claimed in claim 2, where said desiredstructure includes n number of top threads (3 a, 3 b . . . 3 x), wheren=2 . . . 20, and m number of bottom threads (4 a, 4 b . . . 4 x), wherem=1 . . . 20, as shown in FIG. 2 (on which figure: top threads 3 a, 3b−n=2, and bottom threads 4 a, 4 b−m=2).
 4. Manufacturing of amulti-thread single-line chain stitch line, as claimed in claim 2, whereeach top thread is loaded into its individual needle and each bottomthread is loaded into its individual looper.
 5. Manufacturing of amulti-thread single-line chain stitch line, as claimed in claim 4, usinga means for sequentially enabling a required needle and another meansfor sequentially enabling a required looper simultaneously, providingfor the conjunction of one of the top threads with one of the bottomthreads; said required needle and said required looper forming a currentcouple; wherein said current couple is chosen by said pre-determinablesequencing program.
 6. Manufacturing of a multi-thread single-line chainstitch line, as claimed in claim 5, by using a means for providing adesired number of cycles, where each cycle consists of the followingsteps (FIG. 3): After bringing a current couple into the operatingposition: A—passing of the top thread (3 a) through material (1) by theneedle (5 a); passing the loop of the bottom thread (4 a) by the looper(6 a) through the loop of the top thread (3 a); B—extracting needle (5a) out of material (1) engaging the top thread (3 a) loop by looper (6a); C—shifting material (1) to extend the bottom thread (4 a) loop tothe next perforation point; D—passing of the top thread (3 b) throughmaterial (1) by the needle (5 b), further passing the needle (5 b) withthe top thread (3 b) through the bottom thread (4 a) loop; E—passing ofthe bottom thread (4 a) by looper (6 a) through the top thread (3 b)loop and extracting needle (5 b) out of material (1).
 7. Manufacturingof a multi-thread single-line chain stitch line, as claimed in claim 6,where such means for enabling said required needle is a needle revolver;said needle revolver having needle bars located along said needlerevolver's periphery and oriented along its rotation axis. 8.Manufacturing of a multi-thread single-line chain stitch line, asclaimed in claim 7, where said needle revolver provides an action forintertwining said top threads between each other.
 9. Manufacturing of amulti-thread single-line chain stitch line, as claimed in claim 8, wheresuch means for enabling said required looper with one of the bottomthreads is a looper revolver, which has said loopers located along theperiphery of said looper revolver.
 10. Manufacturing of a multi-threadsingle-line chain stitch line, as claimed in claim 9, where said looperrevolver provides a means for intertwining said bottom threads betweeneach other.
 11. Manufacturing of a multi-thread single-line chain stitchline, as claimed in claim 8, where said current couple is formed by oneof said needles and a single looper with one bottom thread loaded in it.12. Manufacturing of a multi-thread single-line chain stitch line, asclaimed in claim 1, consisting of at least three top threads, each topthread forming a loop at the material perforation point in apre-determinable sequence, said loop being conjoined with the next loopat the next perforation point by means of a looper; no thread beingloaded in said looper; said top threads being loaded in their individualneedles; said individual needles being enabled in said pre-determinablesequence, which sequence is variable along the stitch line; and wheresaid pre-determinable sequence is determined by said pre-determinablesequencing program.
 13. Manufacturing of a multi-thread single-linechain stitch line, as claimed in claim 12, wherein said desiredstructure includes n number of top threads (3 a, 3 b . . . 3 x), wheren=3 . . . 20 and wherein said top threads on the top side of thematerial are independent of each other and/or intertwined between eachother (as shown in FIG. 5).
 14. Manufacturing of a multi-threadsingle-line chain stitch line, as claimed in claim 12, by use of a meansfor providing a desired number of cycles, where each cycle consists ofthe following steps (FIG. 6): A—After bringing one of said needles (5a), with one of said top threads (3 a), into the operating position forsaid cycle: passing of the thread (3 a) through material (1) to be sewnby needle (5 a); engaging the thread (3 a) by the looper (6 a) undermaterial (1); B—Extracting needle (5 a) out of material (1) and shiftingsaid material (1) to provide extension of the thread (3 a) to the nextperforation point, forming the thread (3 a) loop; C—Bringing one of saidneedles (5 b), with one of said top threads (3 b), into the operatingposition for said cycle; D—Passing of the thread (3 b) through material(1) by needle (5 b) and passing the thread (3 b) loop through the thread(3 a) loop by the looper (6 a); engaging the thread (3 b) by the looper(6 a) under material (1); E—Extracting needle (5 b) out of said material(1) and shifting material (1) to extend the thread (3 b) to the nextperforation point, forming the thread (3 b) loop; and F—Bringing needle(5 c), with one of said top threads (3 c), into the operating positionfor said cycle; passing of the thread (3 c) through material (1) byneedle (5 c) and passing the thread (3 c) loop through thread (3 b) loopby looper (6 a).
 15. Manufacturing of a multi-thread single-line chainstitch line, as claimed in claim 14, where such means for enabling saidrequired needle is a needle revolver; said needle revolver has needlebars located along said needle revolver's periphery and oriented alongits rotation axis.
 16. Manufacturing of a multi-thread single-line chainstitch line, as claimed in claim 15, where said needle revolver providesan action for intertwining said top threads between each other.
 17. Asewing machine for manufacturing a multi-thread single-line chain stitchline, wherein at least three threads are used, said sewing machinebasically comprising a means for sequentially enabling a requiredneedle, at least one looper, a feed mechanism to feed material to besewn, a drive mechanism to drive said means for sequentially enabling arequired needle, the looper and the feed mechanism, and furthercomprising a means for synchronization thereof, said sewing machineproviding a means for conjoining said threads at the materialperforation points in a pre-determinable sequence, which sequence isvariable along the stitch line, which sequence is obtained by utilizinga pre-determinable sequencing program for conjoining the threads.
 18. Asewing machine for manufacturing a multi-thread single-line chain stitchline, as claimed in claim 17, wherein at least two top threads and atleast one bottom thread are used, and each said top thread is loadedinto its individual needle and each said bottom thread is loaded intoits individual looper, said needles and said looper or looperscomprising said means for conjoining said threads.
 19. A sewing machinefor manufacturing a multi-thread single-line chain stitch line, asclaimed in claim 18, comprising such means for sequentially enablingsaid required needle with one of the top threads and another means forsequentially enabling a required looper with one of the bottom threadssimultaneously, providing for conjunction of one of the top threads withone of the bottom threads; said required needle and said required looperforming a current couple; wherein said current couple is chosen bypre-determinable sequencing program.
 20. A sewing machine formanufacturing a multi-thread single-line chain stitch line, as claimedin claim 19, wherein such means for enabling said required needle is aneedle revolver; said needle revolver has needle bars located along saidneedle revolver's periphery and oriented along its rotation axis; andsaid needle revolver provides an action for intertwining said topthreads between each other.
 21. A sewing machine for manufacturing amulti-thread single-line chain stitch line, as claimed in claim 20,where such means for enabling said required looper with one of thebottom threads is a looper revolver, which has said loopers locatedalong said looper revolver's periphery.
 22. A sewing machine formanufacturing a multi-thread single-line chain stitch line, as claimedin claim 20, where said current couple is formed by one of said needlesand a single looper with one bottom thread loaded in it.
 23. A sewingmachine for manufacturing a multi-thread single-line chain stitch line,as claimed in claim 17, with at least three top threads being loadedinto their individual needles, no thread being loaded in said looper;said individual needles being enabled in said pre-determinable sequence,which sequence is variable along the stitch line; and wherein saidpre-determinable sequence is determined by said pre-determinablesequencing program.
 24. A sewing machine for manufacturing amulti-thread single-line chain stitch line, as claimed in claim 23,where such means for enabling said required needle is a needle revolver;said needle revolver has needle bars located along said needlerevolver's periphery and oriented along its rotation axis.